This is the 3rd year of a 3-year project on articulatory dynamics of speech in patients suffering from apraxia of speech. The aim of the study is to characterize the patterns of articulatory movements displayed by these patients, and to attempt to specify the relation between these patterns and variables such as site and extent of lesion, time since infarct and amount of recovery. The particular aspects of articulatory dynamics being studied are: 1) simple articulatory reaction time; 2) compensatory articulation under bite block conditions; 3) patterns of articulatory velocity and displacement under speech and nonspeech conditions; 4) temporal organization of complete utterances; 5) patterns of coarticulation of lip and jaw movements. Patients are being compared with age and sex-matched normal control subjects on these variables. An additional variable being considered is the relation between articulation and grammatical function in these patients.